• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.411-414
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• 2002

This paper proposed new techniques of rotor position detection for Switched Reluctance Motor(SRM). This technique is very simple and easy to find out rotor position. The main idea uses the impulse responses which have different values between aligned and unaligned. In order to obtain the rotor position, the Impulse applied to the unenergized phases and their responses are analized to control the speed of SRM without shaft sensor, Experimental results verify the feasibility of the proposed method.

• KIEAE Journal
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• v.16 no.2
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• pp.5-10
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• 2016

Purpose: Recently, many public office buildings which were built by curtain wall increased rapidly, but the results of the investigation of the government, these buildings have been found that the heating and cooling thermal load is high, and showed low energy efficiency. Method: To evaluate the effects by applying outdoor louver and indoor blind, which can control solar radiation in order to reduce the heating and cooling load of public office building which was built by glass curtain wall. The heating and cooling load was calculated via Energyplus, building and outdoor louver, indoor blind were modeled by Google sketchup connected to Energyplus. Result: The results of this study were as follows; the case of applying various outdoor louver, the heating and cooling load all decreased as compared to the case without applying outdoor louver, the case of applying indoor blind, the heating and cooling load decreased as compared to the case without applying indoor blind, but indoor blind showed low energy performance comparing outdoor louver.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.192-193
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• 2006

In this paper, a co-axial type ozonizer varied with discharge gap was designed and manufactured for investigating (1) discharge characteristics with variation of output voltage power supply, flow rate and gap distance (2) ozone generation and solubility characteristics with variation of flow rate, gap distance and discharge power. Pure oxygen was used as process gas of the co-axial type ozonizer.

• YAKHAK HOEJI
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• v.2 no.1_2
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• pp.17-21
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• 1953

The following food consumption survey was carried out during the period 16th July 1951 to 17th July 1951 for the purpose of observing the existing refuge food consumption condition in Korea. The investigation was made in the Jeukki Refuge Camp as the most adeguate sample in compliance with the advice of the officers in Pusan city hall. The 31 subject families were sampled by the random sampling method. In the field of this survey, the investigator visited each subject family and weighed the amount of food consumed at each meal; supper, breakfast and lunch, by the investigating tables and balance. There-by, the total consumed amount of food by each family was investigated for one (1) day.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.371-374
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• 2005

As the aging of this society, instead of growing numbers old protective functions of families decreased according to increasing tendency of nuclear families, increasing rates of females' participation of economic activities. Now, the problem of supporting the old is in need of social supporting system the cope with this are based on these factors are like this: 1) It is necessarily the instruction of medical welfare service. 2) The overlapped service is avoided and the service of specialized. 3) Most of the welfare service institution is Seoul and local city hall, so it needs the institution is transferred. 4) It needs the increase the number of home helper. 5) When the service is offered, the government must considers finance, elderly health condition and preference. 6) It needs the department for the welfare service for the old who stay at home.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.334-336
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• 2001

The photovoltaic power generation system has a great future as clean energy instead of fossil fuel which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three-phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller PLL control system and the phase detector of interactive voltage by using do transformation. The proposed inverter system provides a sinusoidal are current for domestic loads and the utility line with unity power factor. The results of the operated from January to October show the system characteristics.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1885-1887
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• 2003

본 연구에서는 공업용으로 널리 사용되고 있는 오존발생법의 하나인 무성방전법을 응용한 고주파 전압인가에 따른 오존발생기를 설계 제작하여 오존생성의 중요한 인자중 하나인 주파수변화에 따른 오존생성특성을 연구하였다.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.381-383
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• 2000

The photovoltaic power generation system has a great future as clean energy instead of fossil fuel which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three-phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller, PLL control system and the phase detector of interactive voltage by using da transformation. The proposed inverter system provides a sinusoidal ac current for domestic loads and the utility line with unity power factor. The results of the operated from January to October show the system characteristics.

• Journal of Climate Change Research
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• v.6 no.2
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• pp.143-158
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• 2015

This study developed the emission intensity estimation method of GHGs by considering the characteristics of the models and time series. The telematics device was installed on the vehicle (OBD-II) to collect information on the operation conditions from each sample vehicle of public authorities. As a result of comparing the mileage distance and fuel consumption, the matching degree is analyzed very high, showed a ${\pm}1{\sim}4%$ error for each vehicle. By comparing driving record diary of vehicles managed by public authorities, this study presents the method that can be used to verify driving information in order to derive the GHGs emission intensity.

• Advances in concrete construction
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• v.12 no.5
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• pp.439-450
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• 2021

In recent years, nano-reinforcing materials are widely utilized in cement composites due to their unique multifunctional properties. This study incorporated multi-walled carbon nanotubes (MWCNTs) into the cementitious composites at ratios of 0.1%, 0.3%, and 0.5%, and investigated their influence on the flowability, mechanical strength, and hydration heat properties. The addition of MWCNTs enhanced the compressive and split tensile strengths approximately by 18-51%. In the semi-adiabatic temperature rise test, the internal hydration heat of the composites reduced by 5%, 9%, and 12% with the increase of MWCNTs in 0.1%, 0.3%, and 0.5%. This study further performed hydration heat analysis and estimated the adiabatic temperature rise, thermal stress, and thermal crack index. The internal hydration heat of the concrete decreased by 5%, 10%, and 13% with the increase of MWCNTs. The thermal stress of the concrete decreased with increase in the addition of MWCNTs, and the obtained temperature crack index was effective in controlling the thermal cracks.